Smoke detector



FIG. 1 is a front perspective view of a smoke detector showing my new design;

FIG. 2 is a rear elevational view;

FIG. 3 is a bottom plan view;

FIG. 4 is a top plan view; and

FIG. 5 is a partial sectional view of the cover only taken along the line 5--5 in FIG. 3. 

The ornamental design for a smoke detector, as shown. 